HE'S GOT MORE ALIASES THAN A CIA OPERATIVE, AND HE'S LIVED THROUGH STUFF MANY RAPPERS CAN ONLY RHYME ABOUT. BUT MF DOOM ISN'T HERE TO FREAK YOU OUT. HE'S HERE TO SAVE HIP-HOP, ONE "HUMAN LIFE" AT A TIME.

In a recording studio somewhere in downtown Atlanta, around ten o'clock on a warm, crickety August evening, the Crunkies are hollering. That's what MF Doom and his wife, Jasmine, call them, the Crunkies - as in, "If you see any Crunkies on your way to the bathroom, tell 'em you're with the Villain." The Villain is Doom; the Crunkies are the young men who come to the studio to hang out, bullshit, and occasionally work on hip-hop records of the amped-up, Dirty South variety. Right now, there's a fiercely competitive Xbox tennis tournament under way in the studio's front lounge, hence the hollering. The room is full of dudes and bluster and good-natured intimidation. Periodically, someone yells "Beleeeda't!" - in a voice that would carry across the most crowded strip club in all of Georgia-as a fistful of fuck-you money changes hands.

The Crunkies are rappers, or would-be rappers, or aspirants to high-ranking appointments in the cabinets of would-be rappers. MF Doom is in the same business, but sometimes he seems like he's not from the same galaxy. This is due inpart to his age-he's in his early thirties, middie-aged by hip-hop standards. But mainly it's the Mask.

The Mask is made of metal. It covers most of his face. Doom is never photographed without it, and when he's around people he doesn't know well, he doesn't take it off. Sometimes if he's eating something unwieldy, like chicken wings, he'll twist it to one side - but that's it. There is a patina of rust on its can-opener jaws.

Jasmine laughs. "I tell him to keep it on," she says. "Don't show your face! You have freedom! You can go to the supermarket! That's beautiful!"

Doom is up late fine-tuning his new album, MM..FOOD, with the help of Jasmine (who also owns Doom's record label, Metal Face) and an engineer named Morgan. He describes the mostly self-produced record as a kind of concept album about "things you find on a picnic, or at a picnic table" - food metaphors and sound bites abound.

While this is a highly nonstandard idea for a hip-hop album, it's standard Doom. This is an MC who has written entire albums in character-rhyming in the voice of a time-traveling "vaudeville villain" named Viktor Vaughn or the third-string Godzilla nemesis King Geedorah. An MC who peppers his lyrics with archaic turns of phrase ("Egads!" or "You're too kind") instead of curse words, and who has thought hard about what rhymes with "Slobodan Milosevic." He is a rap artist whose tracks feel less like rap songs than EKGs of his brain's eccentric contours.

Doom writes like a guy who spends a lot of time chilling in a fortress of solitude with his obsessions and demons. In his lyrics, he's a detached observer, and a sense of alienation pervades much of his work; one minute, he'll be riffing on Jeopardy! or Doritos, then he'll say something like, "Look, Ma, no hands / Studied black magic for years out in no-man's-land," hinting at how deep and how dark the stream of his consciousness runs.

Even when he's working with other people, Doom seems like he's working alone; he's done scores of cameos, but seldom indulges in hip-hop's traditional family-style bonding. So it's appropriately confounding that his best record to date may be this year's Madvillainy, an album-length collaboration with Southern California producer Madlib that's as casual as a blunted freestyle session and as dense and vivid as a fever dream. Doom does note that he and the notoriously reticent Madlib exchanged as few words as possible while making the album, communicating mostly by hand gestures. "I'm learning more from him about being elusive," he says.

The irony, of course, is that all this mystery-draped music has made Doom as famous as underground rappers get. He's on the verge of becoming what Donald Rumsfeld would refer to as a known unknown. Madvillainy has sold an impressive 45,000 copies as of summer; MM..FOOD is the first record he'll make as part of a new deal with Rhymesayers, the Minnesota indie that broke Atmosphere. "I think this one's gonna hit a lot more people," Doom says.

Six years ago, you wouldn't have bet on any of this. Six years ago, before Doom released his debut, Operation: Doomsday, he wasn't just mysterious - he was missing. Long Island-bred Daniel Dumile was a mere teenager when he parlayed a show-stealing cameo on 3rd Bass' 1989 hit single "The Gas Face" into a record deal for his own group, KMD, a playful yet idealistic rap act he'd founded in the late '80s with his younger brother DJ Subroc. Their 1991 Elektra debut, Mr. Hood, mixed the jazzy cleverness of De La Soul with Brand Nubian's pop Afrocentrism. In the video for "Peachfuzz," Dumile/Doom (then called Zev Love X) and Subroc, wearing kufis, hawked essential oils on a New York street corner.

"My mother raised us with Islam," Doom says. "And then my father, being a teacher, always taught us about our people, about Marcus Garvey and the Honorable Elijah Muhammad. But when I started junior high school, I realized motherfuckers didn't know about these people! So I was like, 'Let's spread the word.' We were straight-up teachers."

Their second album, Black Bastards, was something else entirely. Darker than Mr. Hood, it replaced the first album's whimsical Sesame Street samples with sound bites of former Last Poet Gylan Kain dropping the N-bomb and darkly funny portrayals of the 'hood as a moral Waterloo for black men, relayed by narrators too stoned or drunk to be reliable. "They were so young," says 3rd Bass' Pete Nice. "At that point, even a year can change your perspective."

KMD were still working on Black Bastards in 1993 when Subroc was killed in a car accident. Doom finished Black Bastards on his own. At Subroc's funeral, Pete Nice remembers, "Doom had the album playing in the background, which was just surreal"

Still mourning his brother's death, Doom submitted the album to Elektra - complete with a cover depicting KMD's mascot, a cartoon Sambo character, hanging from a noose. The label failed to grasp the irony. Reportedly nervous about a repeat of the controversy stoked by Ice-T's "Cop Killer" - which had landed Elektra's parent company, Warner Bros., in hot water in 1992 - the label dropped KMD.

After that, Doom slipped off hip-hop's radar almost entirely. People in the industry lost contact with him. "I called him around the time his brother passed away," says "Gas Face" producer Prince Paul. "And after that, I didn't know what happened to him. He just kinda disappeared." Doom puts it more directly: "I was damn near on the verge of being homeless."

It's the day after the MM..FOOD studio session, and Doom's sitting on a futon couch in the bedroom of a concrete-bunker apartment in a former meatpacking plant that's been converted into artists' lofts. He stays here when he's working; the rest of the time, he lives about 45 minutes outside of town with Jasmine and his two sons. There's a poster of the periodic table of elements tacked to one wall; on a table, behind an array of recording equipment, are a number of the English-language usage books Doom reads voraciously, such as Merriam-Webster's Dictionary of Allusions and The Dictionary of Clichés and Depraved and Insulting English, for words and phrases. "It bugs me out," Doom says. "Cats are still using the same five curse words. If you take out 'shit,' 'bitch,' 'nigga,' murder,' and 'killa,' mother-fuckin' record would sound like an instrumental!"

He's goofy and open, cracking Heinekens with his teeth and issuing pronouncements about the state of mainstream hip-hop like a high-school graduate remembering the politics of the cafeteria. But he's in control of the conversation, and stays in character; he'll begin to answer a question as Daniel Dumile, like whether he's ever carried a gun, then catch himself and respond as Doom (Doom's answer: "No").

During his hiatus from the business, he says, "each day was basically the same. I'd put my son on the bus in the morning, send him off to school. I might have 50 cents to get a beer, a can of O.E. [Olde English malt liquor]. If I had a dollar, I might get two. At the time, my wife, we were just startin' to date, so she'd come on her lunch break, bring me a sandwich, cheer me up. Most of the time, I was sticking to the crib, broker than a motherfucker, listening to jazz and just writing."

Even without a record deal, or equipment, or a car, Doom kept working. He begged and borrowed studio time, just to put some music on tape. Through Kurious, a NewYork rapper who'd appeared on the Black Bastards cut "Stop Smokin' That Shit," Doom got in touch with Bobbito Garcia, a former Def Jam staffer and KMD fan who'd become a minor mogul inthe burgeoning NewYork underground hip-hop scene. In 1997, Garcia's label, Fondle 'Em, put out the first Doom single, "Dead Bent." "We sold like a thousand copies in a month," Doom says. "White-label single. So I'm like, damn, we do that every month, it'll be on! Then we put out the album, and the album caught some wreck too."

Operation: Doomsday, released in 1999, still sounds utterly original. The backing tracks are mostly warped takes on '80s "Quiet Storm" R&B, all soft-focus bass and pleathery keyboards, the kind of stuff you could imagine playing on the hi-fi in Blair Underwood's bachelor pad. But the lyrics were rough and haunted, full of weird internal rhymes and vertiginous shifts in perspective. Between songs, snippets of an old Fantastic Four cartoon (specifically, dialogue about the origin of FF rival Doctor Doom) acted as a creepy subplot Doctor Doom, after all, wore an iron mask to conceal the scars he'd incurred after a lab experiment-an attempt to resurrect his dead mother-went horribly wrong.

It was around this time that Doom started hiding his face in public. He'd show up to New York hip-hop clubs on open-mic night wearing a stocking mask. He wanted the Doom character to be anonymous, a cipher whose appearance didn't matter. In 1998, with celeb rappers like Puff Daddy building empires based on eye-popping videos, Doom's reticence struck a chord. Of course, wearing a mask is as much a visual gimmick as anything else, but to a growing audience of disen- franchised hip-hoppers, Doom was suddenly a folk hero.

Graffiti artist Lord Scotch, who designed Doom's current mask, believes that the rapper's early success - with 3rd Bass as well as KMD - may have contributed to his desire for a secret identity. "He had some measure of celebrity as a child. He's tasted all that - what it feels like to go to school and have motherfuckers treat you differently. Like, 'Oh, you think you're all that?"

Doom has another theory. "The real reason is, I'm so ugly, I don't wanna distract the crowd when I go out onstage," he says. "I don't know if I'd even get a song done-motherfuckers would be throwin' tomatoes."

He was a straight-up teacher, once, and now he comes crooked, but behind Doom's villainous facade, there's still a hint of Zev Love X's idealism. And when Doom talks about what he wants to accomplish with MM..FOOD, he mentions "showing respect for human life." By rapping about what he had for lunch, he's secretly trying to bring about a profound shift in the hip-hop discourse.

"Let's talk about having children," he says, "as opposed to killing people's children. Like, why say, 'Yeah, if you don't bust ya gun, you're a pussy!'? You know how easy it is to bust a gun? You might as well pick something more interesting, like - jump in a pool! That's about as easy as bustin' a gun, but you ain't hurtin' nobody! Let's all go swimming! If you ain't swimming, you wack!"